Some Supplement-Medication Combinations Make Dangerous Mix

Nov. 15, 2010 — -- Long before prescription medications, our ancestors relied solely on certain plants, perhaps even a combination of herbs, anecdotally known to cure what ailed them.

While many of us still swear by the natural ingredients, commonly used in the unnatural form of supplements, our modern impulses may tell us to trust the best of both worlds -- combining prescription medications and supplements.

But too much of a good thing may be bad for you.

Certain combinations of supplements with medications might decrease the chance the medication will work, but many patients don't know it, Jennifer Strohecker, a clinical pharmacist at Intermountain Medical Center in Salt Lake City, Utah said Monday at the American Heart Association annual scientific meeting.

Strohecker and her colleagues surveyed 100 patients on the blood thinner warfarin and found more than two-thirds used supplements, some of which may decrease the effects of the medication and put them at higher risk for internal bleeding or stroke. Yet, only one-third told their doctor they were taking supplements.

Some of the supplements patients reported taking included glucosamine, chondroitin and coenzyme Q10, which could interfere with warfarin, Strohecker said.

It signals a major communication gap between patients and physicians, she said.

In fact, according to the survey, 92 percent of those taking supplements may not have thought to share the information but would have told their doctor, had they only been asked.

"Everybody has a job to do," said Keith Ayoob, director of the nutrition clinic at the Rose R. Kennedy Center at the Albert Einstein College of Medicine in the Bronx, N.Y., who said it's easy for doctors to overlook the potency of supplements.

Many conventional doctors are not well educated in herbs and supplements, said Ayoob.

Still, herbal and diet supplements are among the fastest growing industries, said Strohecker. While she did not discourage patients from taking supplements, she said physicians should educate themselves and their patients about using them safely.

"Patients are using more supplements, so I as a health care provider need to be the information source for my patients," said Strohecker.

Ayoob agreed.

"Patients need to tell and doctors need to ask," said Ayoob.

Are Supplements Necessary?

According to a 2009 Nielsen study, 44 percent of Americans say they use supplements every day -- helping to create the $25 billion industry. But many don't understand why they take them or whether they need to take them at all.

Some supplement labels claim that what's inside the products will help guard against illness. Others claim people are not getting enough nutrients in a day.

But for many, supplements may not be the answer to staying healthy.

"If we really look at the data on vitamins and minerals, there isn't a whole lot there," said Dr. Donald Hensrud, associate professor of Nutrition and Preventive Medicine at the Mayo Clinic in Rochester, Minn.

In fact, it is possible to overdose on vitamins without combining it with other medications, said Ayoob.

"If you take too much of one, you might offset how another one works," he said. "Sometimes, minerals don't mix well together."

The U.S. Food and Drug Administration does not regulate safety of supplements as rigorously as foods or medications.

"There isn't a lot of regulation regarding quality control, safety or efficacy," said Hensrud. "It's somewhat of a buyer beware [situation]."

Supplements Show Benefit for Some

While some supplements are marketed to work for a variety of ailments, there's no scientific data to back all of the claims.

All women of childbearing age are advised to take folic acid to prevent neural tube defects in their child. However, some studies discredit claims that folic acid and other B vitamins prevent prostate cancer, colon cancer or heart disease.

For some, however, supplements can be beneficial, said Ayoob.

In fact, only 3 to 4 percent of Americans follow all of the dietary guidelines, according to 2009 position paper published by the American Dietetic Association.

"Some things are difficult to get [from food] for some people," said Ayoob.

Among those are vitamin D, which most often is gained through appropriate exposure to sunlight, tuna, salmon or fortified milk. Many Americans are deficient in vitamin D, he said.

Other examples include osteoporosis patients who may need calcium supplements, or smokers who are at higher risk for vitamin C deficiency.

Still, Ayoob said, "You're never going to get from a pill what you get from healthy food."